The present invention relates to industrial circuit breakers and particularly to apparatus for indicating the condition thereof.
The subject condition indicator apparatus has particular application to store energy reclosure type circuit breakers, such as that disclosed in commonly assigned, copending application Ser. No. 52,276, filed June 25, 1979 now Pat. No. 4,251,702. The disclosure of this copending application is specifically incorporated herein by reference. As therein disclosed, a circuit breaker is equipped with a separate spring-powered charging mechanism which is charged and then discharged to charge a spring-powered operating mechanism capable, when charged, to propel breaker movable contacts from a tripped open position to a closed position and, when discharged or tripped, from their closed position to their tripped open position. A hook is utilized to releaseably hold the movable contacts in an intermediate hooked open position against the closing force of a charged operating mechanism. Thus, the hook, in effect, stores the charge in the operating mechanism for subsequent utilization to motivate closure of the circuit breaker. A prop sensitive to the condition of the operating mechanism is utilized to store a charge in the charging mechanism while the former is in a charged condition, i.e., the movable contacts are in either of their hooked open or closed positions. When the charged operating mechanism is discharged, the movable contacts are propelled to their tripped open position effective in removing the prop, and the charge stored in the charging mechanism is automatically expended in recharging the operating mechanism. The circuit breaker is thus rendered capable of reclosure.
In a circuit breaker having such reclosure capability, it is important to indicate not only whether the breaker contacts are open or closed, but also whether a charge is stored in either the operating mechanism by the hook or the charging mechanism by the prop, and thus indicate whether or not the circuit breaker is capable of reclosure regardless of the position of the movable contacts.
It is accordingly an object of the present invention to provide improved condition indicator apparatus for utilization in spring-powered reclosure type circuit breakers.
A further object is to provide indicator apparatus of the above character for indicating whether the breaker contacts are open or closed.
Another object is to provide indicator apparatus of the above character for indicating whether or not the breaker is capable of closure while its contacts are open and whether or not the breaker is capable of reclosure while the breaker contacts are closed.
An additional object is to provide condition indicator apparatus of the above character which is efficient in construction and reliable in operation.